This invention is directed to loudspeaker systems and in particular to loudspeaker systems for use as a loudspeaker telephone terminal.
Telephone apparatus is normally designed to acoustically isolate the microphone from the loudspeaker to assure the prevention of sing-around paths. However, it has become desirable to operate the telephone in a hands-off manner so that other tasks may be performed while talking over the telephone, and more essentially so that one or more groups of people may talk and listen at various locations in the form of a conference.
Loudspeaker telephone apparatus which has been developed to allow hands-free operation, operates on the basis that at each location, the apparatus is voice-switched such that when a person speaks into the microphone, at one location, a switch operates to disconnect the speaker at that location. This type of system operates quite satisfactorily for a conversation between two people at two locations, however, as the number of telephone locations in a conversation or telephone conference increases, the chances of two people speaking at the same time increases. To avoid this situation in which two or more loudspeakers are off at the same time, the conference must become very formal with the interplay of participants being controlled by a chairman.